analysis of water injection into high-temperature mixture of ...

54Temperature (K)-3.60-3.50-3.40-3.30-3.20-3.100.1Nw/Nf0.15Nw/Nf0.2Nw/Nf0.8 0.9 1.0 1.1 1.2Equivalence ratioFIGURE 4-36 The temperature change of gases burned with Equivalence ratioAccording to Figure 4-35 and Figure 4-36, these can be shown that the relativetemperature change of water injected and gases burned which can be seen from curvesare almost the same. This reason of change resembles with compression ratio as theheat loses in cylinder into the water zone, varied with different molar water injectionfuelratio. However, it is very much difference both at stoichiometric. Thetemperature of water injected increases value almost 1,000 K, but temperature ofgases burned decreases almost the same value, which can be compared with otherequivalence ratios. It follows a similar trend from the section 4.6.1.2 but be value lessthan that section. The relative temperature change of water injected, figure can beseen that the temperature increase and temperature change of gas burned, figure canbe seen that the temperature decrease. Results are approximately increased value of100-1000 K per 1 CA of water injected and decreased valued of 3.2-3.6 K per 1 CAof gas burned, these depend on compression ratio. When considering relativeequivalence ratio increases, it makes the mass of water injected increases under theequally pressure. However, volume of water zone at high compression ratio more thanat low compression ratio. Thus, the temperature change of water injected must bedecreases and led to increase in the temperature of gases burned.4.6.2.3 Simulation with variation of engine speed. This simulation test wasrun at 2,000 rpm, compression ratio 10 while using molar water injection-fuelratio ( XW) such as 0.1 , 0.15 and 0.2 . These applications were used the differentengine speed (RPM) varied from 1000, 1500, 2000 and 2500, respectively andfollowed the schematic from Figure 3-2 and assumption from 3.3.2.